The present invention relates in general to an information storage device having an information storage medium which is disposed in a removable cartridge and, more particularly, to a method and apparatus for ensuring that such a drive is operationally compatible with a removable cartridge inserted into it.
Over the past twenty years, computer technology has evolved very rapidly. One aspect of this evolution has been a progressively growing demand for increased storage capacity in memory devices, especially where the information storage medium is disposed in some form of removable cartridge. In this regard, just a little over a decade ago, the typical personal computer had a floppy disk drive which accepted floppy disk cartridges that contained 5.25xe2x80x3 disks having a storage capacity up to about 720 KB per cartridge. Not long thereafter, these devices gave way to a new generation of floppy disk drives which accepted smaller floppy disk cartridges that contained 3.5xe2x80x3 disks having higher storage capacities, up to about 1.44 MB per cartridge.
Subsequently, as the evolution continued, a further significant increase in storage capacity was realized in the industry by the introduction of a storage system having removable cartridges containing floppy-type disks with storage capacities on the order of 100 MB to 250 MB. Systems of this are commercially available under the tradename ZIP from Iomega Corporation of Roy, Utah, which is the Assignee of the present application. Thereafter, another significant increase in storage capacity was realized by the introduction of a system having removable cartridges with storage capacities on the order of 1 GB to 2 GB. Systems of this type are also available from Iomega Corporation, under the tradename JAZ. The cartridges used in this system had a hard disk in an unsealed housing, with the read/write head in the drive. These two products have each enjoyed immense commercial success. Nevertheless, the demand for still greater storage capacities in removable cartridges continues to progressively increase, such there is a current need for cartridges capable of storing 5 GB to 20 GB, or even more.
The types of removable cartridges discussed above each contain a rotatably supported storage medium within an unsealed housing. The read/write heads, with associated circuitry and support structure, are in the drive rather than in the cartridge. Significantly higher storage capacities exist in hard disk technology of the type used in non-removable hard disk drives, where the disk and head are both within a sealed housing. However, there are problems involved in attempting to carry use of this technology over to removable cartridges. This is due in part to the fact that a high-capacity hard disk is highly sensitive to environmental factors such as dust and static electricity. Consequently, in order to achieve high storage densities, the sealed housing is needed for the hard disk itself, as well as for some associated components, such as the read/write heads, which must be within the sealed housing and thus within the cartridge. Although some prior attempts have been made to use hard disk technology within a sealed housing in a removable cartridge, these attempts never resulted in a product which has had any significant level of commercial success. Instead, the types of cartridges discussed above continue to dominate the market.
Where a sealed housing has been used, the most typical prior approach was to incorporate the entire structure of a hard disk drive unit into the cartridge, such that the cartridge was not significantly different from a self-contained, standalone hard disk drive unit. In a sense, this was not a true cartridge at all, but simply a complete and self-contained hard disk drive which could be removed more easily than most from the system in which it was installed. One example of such a device is a system which was commercially available as the model P3250AR removable hard disk drive from Kalok Corporation of Sunnyvale, Calif. Another example of such a system is disclosed in Blackborow et al. U.S. Pat. No. 5,041,924. Since each cartridge in this type of system is effectively a standalone, self-contained disk drive, each cartridge is relatively heavy and expensive.
A different prior approach was to split the components of a self-contained hard disk drive into two groups, and to include one group within a sealed housing in each removable cartridge, and the other group in a drive which can removably receive one of the cartridges. Examples of this approach appear in Stollorz U.S. Pat. No. 4,359,762, Iftikar et al. U.S. Pat. No. 4,965,691, Chan U.S. Pat. No. 5,214,550, Kamo et al. U.S. Pat. No. 5,235,481, Witt et al. U.S. Pat. No. 5,317,464, and Lockhart et al. U.S. Pat. No. 5,412,522. While pre-existing products using this approach were adequate for their intended purposes, they were not satisfactory in all respects, and none of them experienced any significant commercial success.
In this regard, one consideration is that, where circuitry in a drive effects alignment of a read/write head with a disk using feedback servo control, the drive must be aware of certain servo parameters which define appropriate control characteristics that are to be used with that particular type of hard disk. If a given drive was limited to use with only a single type of cartridge, then this information could be permanently stored in the drive. However, where the drive is to be used with various different types of cartridges, some of which may not have been developed at the time the drive is manufactured and sold, it is desirable that the drive be able to automatically determine, in response to insertion of a cartridge, what servo parameters should be used to effect feedback servo control in order to effect successful operation with that cartridge. It would be desirable to achieve this in a manner which uses little or no additional electrical and mechanical structure within the cartridge, and which involves little or no increase to the cost of the cartridge.
Another consideration is that, in order to successfully operate with some new cartridges, a drive may need to know more than just the servo parameters applicable to that cartridge. In particular, it may be necessary to update firmware disposed in the drive in order to make the drive operationally compatible with the new type of cartridge. Existing techniques for upgrading the firmware, such as returning the drive to the factory, or loading and executing a special upgrade program through an associated host system, can be highly inconvenient. Accordingly, it is desirable to have an improved technique for upgrading firmware in a drive so as to render the drive operationally compatible with a new type of cartridge.
From the foregoing, it will be appreciated that a need has arisen for a method and apparatus for ensuring that a drive is operationally compatible with a removable cartridge which is inserted into it.
According to one form of the present invention, a method and apparatus are provided to address this need for an information storage cartridge which has a port and an information storage medium with an information storage surface. The method and apparatus involve: storing on the information storage surface information which includes control information; supporting the storage medium and a head for relative movement in a manner causing the head to move relative to the surface while remaining adjacent thereto; transferring information between the port and the storage medium, including use of the head to effect at least one of reading information from and writing information to the storage medium; reading the control information from the information storage surface using the head; and thereafter effecting the relative movement of the head and the storage medium as a function of the control information.
According to a different form of the present invention, a method and apparatus are provided to meet the need for an information storage cartridge which includes a port, an information storage medium, and structure for transferring information between the port and the information storage medium. The method and apparatus involve: storing a first program in the information storage medium; providing a receiving unit which can removably receive the cartridge, which has a port that operatively cooperates with the port of the cartridge when the cartridge is received in the receiving unit, and which can communicate with the cartridge through the ports when the cartridge is received in the receiving unit; storing a second program in a memory provided in the receiving unit; providing a processor which can execute the program stored in the memory; and effecting an upgrade during an operational mode when the cartridge is removably received in the receiving unit, the upgrade including the operations of reading the first program through the ports from the information storage medium in the cartridge, and storing the first program in the memory in place of the second program.